In the wrap-around labeling of bottles it has been a common practice to form heat shrinkable, plastic labels from a web of labels, into sleeves, by winding the label about a mandrel with overlapped edges of the label being heat sealed together. These sleeves are then assembled about the bottle and then passed through a heat shrink tunnel to cause the sleeve to shrink against the external surface of the bottle. In this way a bottle is provided with a thermoplastic sleeve label which may conform to the shoulder contour of the bottle and even be shrunk around the heel and beneath the bearing surface. Such a system is disclosed in U.S. Pat. No. 3,802,942.
A more recent U.S. Pat. No. 4,574,020, issued 3/4/86, discloses a process of applying labels to bottles in which a web of plastic label material is cut into label lengths and transported on the surface of a vacuum transfer drum. The vacuum drum is rotated about its vertical axis and has raised areas on its surface which underlie the leading and trailing edges of the cut labels. A gravure roll having a supply of solvent applied to its surface rotates about an axis parallel to the drum axis and is adapted to apply solvent to finite areas of the label at the trailing and leading edges. The label is then carried on the drum to a point where its leading edge meets the side wall of a bottle and becomes adhered thereto. The bottle is then rolled along the surface of the drum to wind the label thereabout until the trailing edge of the label overlaps the leading edge and sticks thereto to form a complete sleeve that is adhered to the bottle. The bottle with the label thereon is then passed through a heated tunnel to circumferentially shrink the sleeve label into relatively tight conformity with the external configuration of the bottle.
In this process set forth above, it is important that the bottle axis be vertical when the leading edge of the label is first stuck to the side of the bottle so that, upon complete wrapping of the label about the bottle, the leading edge and trailing edges will be in exact horizontal alignment. Otherwise, if the labels are not in precise alignment, a "mismatch" occurs and the subsequent shrinkage may result in an unsightly label. Unless the axis of the bottle is held vertical, at the time the label first touches the sidewall thereof, the resultant rolling of the label on the bottle will leave the trailing edge of the label at an angle and it will not line up with the underlying leading edge.
Another important consideration to handling the bottles through the label applicating system of the invention is the movement of the labeled bottle through what is termed a "secondary roll-on section" where the bottle is rolled with its sidewall in contact with an elongated resilient pad to assure that the overlap of the trailing edge is over the leading edge firmly pressed together. This application of pressure to the overlap seam is carried out by rolling the bottle over a polyurethane pad whose vertical shape parallels the shape or vertical contour of the generally round bottle. The bottle is, in effect, gripped between the vacuum drum and a primary pad for the initial application of the label and then is passed to a secondary roll-on pad while being moved by a horizontally moving belt that has a vertical surface in parallel to the secondary pad.
It is thus an object of the present invention to apply a label to a container or bottle where the bottle serves as a mandrel upon which the label is wound into a full overlapping sleeve that is adhered to itself with the top and bottom edges of the labels being in registry at the overlap seam and then engaging the seam with a pressing pad to assure the formation of a complete vertical seam.
Other objects will be apparent from the following description taken in conjunction with the annexed sheets of drawings.